With development of wireless communications technologies and an increase in requirements imposed by people on wireless communications services, wireless frequency occupied devices are increasingly large in quantity. A radio spectrum is a finite and non-renewable natural resource, and therefore, it is quite necessary to implement scientific, effective, and uniform management on spectrum resources and frequency occupied devices, so as to improve spectrum utilization and a spectrum management capability. By means of spectrum management, some spectrums are allocated to unlicensed users for use, and the spectrums become unlicensed spectrums. In the unlicensed spectrums, a 5-GHz bandwidth has not been widely applied currently, and therefore, application of an LTE (Long Term Evolution, Long Term Evolution) technology to 5 GHz becomes a trend. LTE is a next evolution target of a mobile broadband network standard defined by 3GPP (3rd Generation Partnership Project, 3rd Generation Partnership Project), and may implement efficient use on conventional and future wireless frequency bands. A higher applied frequency band (such as 5 GHz) indicates quicker electric wave propagation attenuation, and a shorter transmission distance, and therefore, an LTE-Advanced (LTE-A, LTE-Advanced) technology is introduced, that is, LTE-A is subsequent evolution of the LTE technology.
In the LTE-A technology, a relay node (RN, Relay Node) responsible for transferring and receiving a radio signal is added to an architecture of an access network. As shown in FIG. 1, FIG. 1 is a schematic diagram of a network architecture of conventional LTE-A. In FIG. 1, a radio link between user equipment (UE, User Equipment) and an RN is an access link, and an air interface of the radio link may be referred to as a Uu interface. A radio link between the RN and a donor eNodeB (DeNB, Donor eNB) is a backhaul link, and an air interface of the radio link may be referred to as a Un interface. The DeNB and a mobility management entity/serving gateway (MME/SGW, Mobility Management Entity/Serving Gateway) of a core network are connected to each other by using an S1 interface. The DeNB mainly provides routing relay functions of the S1 interface and an X2 interface, and is used to transit connection between the RN and another node, and the RN used as a cell is mainly used to transmit data, and used to supplement coverage and improve system capacity. When needing to communicate with the MME, the UE needs to be connected to the MME by using the S1 interface of the RN and by means of the DeNB. In this case, the RN seems to directly transfer a data stream to the MME. Therefore, messages and data sent by the S1 interface all first reach the DeNB, and then forwarded to the RN or the core network, and in this process, the DeNB provides only the routing relay function of the S1 interface.
Generally, the RN is a low-power node, and responds to relatively small RN coverage, which cannot ensure business continuity in a high-speed movement scenario. Moreover, because a serial transmission manner is used for the S1 interface, data can be sent to the user equipment by using only the RN node, and in a scenario such as a network congestion scenario or an RN coverage boundary scenario, resource utilization of the donor eNodeB and the RN node cannot be effectively and dynamically coordinated, and optimal performance of a system cannot be achieved.